This proposal is for the purchase of a Complex Object Parametric Analyzer and Sorter (COPAS) for Drosophila. This instrument is capable of sorting large quantities of genetically modified Drosophila embryos. This is a recently available technology that enables a variety of functional genomics investigations including 1) Gene expression microarray experiments using mutant animals. 2) Chromatin-DNA co- immunoprecipitation experiments using mutant Drosophila embryos, and 3) Novel genetic screens based on activation or deactivation of GFP fluorescence in transgenic animals. We propose to purchase this instrument for these immediate uses by Yale Investigators. We realize that this new instrumentation will allow for a wide variety of genomics applications in Drosophila, and we expect that for the first year of operation, the initial user group will demand most of the available time on the instrument. However, as it is the case for most new instrumentation that allows research that was previously exceedingly technically difficult or impossible, we expect that the user group will grow at Yale. From the onset, we will employ a system of usage tracking and management in order to maximize the utility of this instrument to the local community of investigators who use Drosophila in their research.